Testing metric-affine f(R)-gravity by relic scalar gravitational waves

Testing the Metric-Affine Gravity Using Particle Dynamics and Photon Motion

This work mainly focuses to unveil the optical features of a black hole. For this objective, we utilize the metric-affine black hole geometry with the inclusion of dilation, spin, and shear charge. The Lagrangian coefficients $f_1$ and $d_1$ are the main parameters, where $f_1<0$, which differentiate the solutions by $d_1=8f_1,\;d_1=-8f_1,\;\&\;d_1=\pm8f_1$. Based on these parameters, we carry out this work in two cases, i.e., $d_1=8f_1,\;\&\;d_1=-8f_1$. We forecast the detailed impact of dilation, spin, and shear charges on the optical properties of the black holes in both cases. To unreveal …

Testing string cosmology with gravity wave detectors

The general properties of the gravity wave backgrounds of cosmological origin are reviewed and briefly discussed, with emphasis on the relic background expected from an early pre-big bang phase typical of string cosmology models.

From fundamental physics to tests with compact objects in metric-affine theories of gravity

This work provides a short but comprehensible overview of some relevant aspects of metric-affine theories of gravity in relation to the physics and astrophysics of compact objects. We shall highlight the pertinence of this approach to supersede General Relativity on its strong-field regime, as well as its advantages and some of its difficulties. Moreover, we shall reflect on the present and future opportunities to testing its predictions with relativistic and non-relativistic stars, black holes, and other exotic horizonless compact objects.

基于LIGO数据的典型遗迹引力波约束

Constraints on typical relic gravitational waves based on data of LIGO

本文利用卷积神经网络在LIGO O2、O3a和O3b数据中搜寻暴胀及一阶相变产生的遗迹引力波，未发现信号并给出谱能量密度上限10^{-5}，所提方法可推广至O4等未来数据。

An infinite class of exact rotating black hole metrics of modified gravity

We build an infinite class of exact axisymmetric solutions of a metric-affine gravity theory, namely, Eddington-inspired Born-Infeld gravity, coupled to an anisotropic fluid as a matter source. The solution-generating method employed is not unique of this theory but can be extended to other Ricci-Based Gravity theories (RBGs), a class of theories built out of contractions of the Ricci tensor with the metric. This method exploits a correspondence between the space of solutions of General Relativity and that of RBGs, and is independent of the symmetries of the problem. For the particular case in…

焦点专题：从早期到晚期宇宙的宇宙学张力：第二部分：最现代天文设施观测启示下的新方向

Focus Point on Tensions in Cosmology from Early to Late Universe: Part II: New Directions in the Light of Observations from the Most Modern Astronomical Facilities

该专题聚焦最新观测带来的宇宙学张力，涵盖LARES-2检验参考系拖曳、PINN分析银河系中心S星数据、遗迹引力波转化与随机背景产生及Starobinsky暴胀模型预言等新方向。